DESCRIPTION: (Applicant's abstract) With this improved detection of co-resident labels, MPD technology enables more effective SC to be implemented. Because of its ability to specifically detect co-resident lahels attached to minority species in a heterogeneous DNA sample, MPD will also serve to "point out" Unique candidates prior to any laborious manipulations of individual clones. With MPD-Imager already operational, the major objective of this proposed R&D is to develop simplified RDA. One of the most important features of MPD technique is that it enables the DNA/RNA quantitation down to a few templates level. This will enable a totally new type of Unique DNA studies, namely quantitative studies of Unique DNA at a single cell level. This capability will be very important in embryogenesis studies. It will open totally new possibilities in studies of cellular differentiation, e.g. in studies of stem cell differentiation. All these applications requires use of very limited amount of material and can not be performed vith current RDA procedures. In proposed R&D, several improvements in RDA will be implemented and optimized. Such improvements will lead to the development of reagent kits containing "cookbook" protocols for RDA. This will establish RDA as a standard laboratory technique in contrast to its current status as a heroic undertaking for the few expert teams. The complementing MPD instrumentation is now moving from the prototype stages into commencal production. Also, the RDA specific software has been recently developed.